导出execl

　　　　　　　string filepath = Utils.GetMapPath("/upload/excel/");
            filepath = filepath + fileName + ".xls";
            string tempFilePath = Utils.GetMapPath("/ExcelTemplate/export_comment_excel.xlsx");

            DataSet ds = new BLL.Comment().GetList(0, strWhere, "addtime desc");

            DataTable exportDT = new DataTable();
            exportDT.Columns.Add("姓名", typeof(string));
            exportDT.Columns.Add("评价等级（星星数）", typeof(int));
            exportDT.Columns.Add("评价内容", typeof(string));
            exportDT.Columns.Add("评价时间", typeof(string));
            exportDT.Columns.Add("状态", typeof(string));
            exportDT.Columns.Add("原因", typeof(string));

            if (ds != null && ds.Tables[0].Rows.Count > 0)
            {
                for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
                {
                    DataRow dr = exportDT.NewRow();
                    dr["姓名"] = ds.Tables[0].Rows[i]["Name"].ToString();
                    dr["评价等级（星星数）"] = ds.Tables[0].Rows[i]["level"].ToString();
                    dr["评价内容"] = ds.Tables[0].Rows[i]["content"].ToString();
                    dr["评价时间"] = ds.Tables[0].Rows[i]["addtime"].ToString();
                    dr["状态"] = GetStatus(ds.Tables[0].Rows[i]["status"].ToString());
                    dr["原因"] = ds.Tables[0].Rows[i]["reason"].ToString();
                    exportDT.Rows.Add(dr);
                }
            }

            Common.ExcelToData.ExportExcel(tempFilePath, filepath, exportDT, "评论信息");

 　　　　　　 GC.Collect();//行销毁   
            HttpContext.Current.Response.Buffer = true;
            HttpContext.Current.Response.Clear();
            HttpContext.Current.Response.ContentType = "application/ms-excel";
            HttpContext.Current.Response.AddHeader("Content-Disposition", "attachment;filename=" + fileName + "(" + DateTime.Now.ToString("yyMMddHHmm") + ").xls");
            HttpContext.Current.Response.WriteFile(filepath);
            HttpContext.Current.Response.Flush();
            File.Delete(filepath);

            HttpContext.Current.Response.End();